test: add Vitest unit tests + CI workflow, fix angular-eslint v22 config

.browserslistrc

@@ -0,0 +1,10 @@
+# Browsers the app supports (also drives the esbuild output target).
+# Without this, browserslist falls back to `defaults`, which pulls in pre-2020
+# engines (Opera Mini, KaiOS, old UC) that lack top-level await — breaking the
+# Angular unit-test build. This is the standard Angular CLI matrix.
+last 2 Chrome versions
+last 1 Firefox version
+last 2 Edge major versions
+last 2 Safari major versions
+last 2 iOS major versions
+Firefox ESR

.github/workflows/ci.yml

@@ -0,0 +1,46 @@
+name: CI
+
+# Run lint + unit tests on every pull request targeting master.
+on:
+  pull_request:
+    branches: [master]
+
+# Cancel an in-progress run when the PR gets new commits.
+concurrency:
+  group: ci-${{ github.ref }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read
+
+jobs:
+  test:
+    name: Lint & test
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      # pnpm must be installed before setup-node so its cache can resolve the store.
+      # Version comes from the "packageManager" field in package.json.
+      - name: Set up pnpm
+        uses: pnpm/action-setup@v4
+
+      - name: Set up Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      # Formatting / linting gate — ESLint flat config (eslint.config.mjs).
+      # Fails the build on errors; tracked `no-explicit-any` warnings do not fail it.
+      - name: Lint & format check
+        run: pnpm lint
+
+      # Unit tests run headless in Node via Vitest (jsdom) — no browser required.
+      # Invoke ng directly so --watch=false isn't swallowed by the npm-script `--`.
+      - name: Run unit tests
+        run: pnpm exec ng test --watch=false

angular.json

@@ -70,6 +70,12 @@
             },
             "ci": {
               "progress": false
+            },
+            "test": {
+              "polyfills": [
+                "zone.js",
+                "zone.js/testing"
+              ]
             }
           }
         },
@@ -97,32 +103,14 @@
           }
         },
         "test": {
-          "builder": "@angular/build:karma",
+          "builder": "@angular/build:unit-test",
           "options": {
-            "main": "src/test.ts",
-            "polyfills": "src/polyfills.ts",
+            "buildTarget": "app:build:test",
             "tsConfig": "src/tsconfig.spec.json",
-            "karmaConfig": "src/karma.conf.js",
-            "styles": [],
-            "scripts": [],
-            "assets": [
-              {
-                "glob": "favicon.ico",
-                "input": "src/",
-                "output": "/"
-              },
-              {
-                "glob": "**/*",
-                "input": "src/assets",
-                "output": "/assets"
-              },
-              "src/manifest.json",
-              "src/manifest.webmanifest"
-            ]
+            "runner": "vitest"
           },
           "configurations": {
             "ci": {
-              "progress": false,
               "watch": false
             }
           }

eslint.config.mjs

@@ -1,14 +1,12 @@
 // @ts-check
-// Flat ESLint config (ESLint 10 + angular-eslint 21).
-// Uses the individual angular-eslint / typescript-eslint plugins directly,
-// since the `angular-eslint` / `typescript-eslint` meta-packages are not installed.
-import tsParser from '@typescript-eslint/parser';
-import tsPlugin from '@typescript-eslint/eslint-plugin';
-import angular from '@angular-eslint/eslint-plugin';
-import angularTemplate from '@angular-eslint/eslint-plugin-template';
-import templateParser from '@angular-eslint/template-parser';
+// Flat ESLint config (ESLint 10 + angular-eslint 22).
+// angular-eslint 22 moved its rule presets out of the @angular-eslint/* plugins
+// and into the `angular-eslint` meta-package, so the recommended rule sets are
+// pulled from there (and from `typescript-eslint`) via the tseslint.config helper.
+import tseslint from 'typescript-eslint';
+import angular from 'angular-eslint';
 
-export default [
+export default tseslint.config(
   {
     // src/assets holds the static Harvard Classics reading content (raw HTML,
     // not Angular templates) — never lint it.
@@ -17,19 +15,14 @@ export default [
   // TypeScript source files.
   {
     files: ['**/*.ts'],
-    languageOptions: {
-      parser: tsParser,
-      sourceType: 'module',
-    },
-    plugins: {
-      '@typescript-eslint': tsPlugin,
-      '@angular-eslint': angular,
-    },
+    extends: [
+      ...tseslint.configs.recommended,
+      ...angular.configs.tsRecommended,
+    ],
+    processor: angular.processInlineTemplates,
     rules: {
-      ...tsPlugin.configs.recommended.rules,
-      ...angular.configs.recommended.rules,
       // This app is intentionally NgModule-based with constructor DI (see CLAUDE.md);
-      // these v21 defaults push the opposite architecture, so they're disabled here.
+      // these defaults push the opposite architecture, so they're disabled here.
       '@angular-eslint/prefer-standalone': 'off',
       '@angular-eslint/prefer-inject': 'off',
       // `any` is pervasive and tracked as a Known Issue — surface it without blocking lint.
@@ -39,14 +32,9 @@ export default [
   // Angular HTML templates.
   {
     files: ['**/*.html'],
-    languageOptions: {
-      parser: templateParser,
-    },
-    plugins: {
-      '@angular-eslint/template': angularTemplate,
-    },
-    rules: {
-      ...angularTemplate.configs.recommended.rules,
-    },
+    extends: [
+      ...angular.configs.templateRecommended,
+    ],
+    rules: {},
   },
-];
+);

package.json

@@ -40,12 +40,12 @@
     "zone.js": "~0.16.2"
   },
   "devDependencies": {
-    "@angular/build": "^22.0.1",
     "@angular-eslint/builder": "22.0.0",
     "@angular-eslint/eslint-plugin": "22.0.0",
     "@angular-eslint/eslint-plugin-template": "22.0.0",
     "@angular-eslint/schematics": "22.0.0",
     "@angular-eslint/template-parser": "22.0.0",
+    "@angular/build": "^22.0.1",
     "@angular/cli": "~22.0.1",
     "@angular/compiler": "~22.0.1",
     "@angular/compiler-cli": "~22.0.1",
@@ -55,16 +55,20 @@
     "@types/node": "~25.9.3",
     "@typescript-eslint/eslint-plugin": "^8.61",
     "@typescript-eslint/parser": "^8.61",
+    "angular-eslint": "^22.0.0",
     "eslint": "^10.5.0",
     "eslint-config-airbnb": "^19.0.4",
     "eslint-config-prettier": "^10.1",
     "eslint-plugin-import": "^2.32.0",
     "eslint-plugin-jsx-a11y": "^6.10.2",
     "eslint-plugin-prettier": "^5.5.6",
     "eslint-plugin-react": "^7.37.5",
+    "jsdom": "^29.1.1",
     "prettier": "^3.8.4",
     "ts-node": "~10.9.2",
-    "typescript": "^6.0.3"
+    "typescript": "^6.0.3",
+    "typescript-eslint": "^8.61.0",
+    "vitest": "^4.1.8"
   },
   "packageManager": "pnpm@11.7.0"
 }